Use of light gauge metal as an element in a wall, floor or roof assembly has had only limited use, which has generally been that of end supports or foundation elements in a position transverse to the end of a support beam or the like. The same is reflected in such references as U.S. Pat. No. 6,205,727 (2001) to Butler, entitled Interlocking Corrugated Panel Wall Cast In-Situ.
The present invention recognizes the potential application of so-called light gauge metal, i.e., steel, aluminum or alloy metal having a gauge in a range of about 0.5 to about 18 mm. for the formation of a surface having a repetitive sequence of ridges and grooves, e.g., corrugations. Therein, such elements are employed as a center support means and truss substitute within a larger constructional assembly in the nature of an internal part of a floor or ceiling structure. The prior art does not, to the knowledge of the inventor, suggest such a constructional assembly or the use of corrugated light gauge steel in such a fashion.
The truss 16 of the U.S. Pub. Patent Appln. 2008/0141612 to Schierding is not a structure similar in function to that of my system. Schierding claims no feature comparable to my fasteners in which a substantially horizontally disposed upper elongate collar-like members are independently fastened to both a hollow re-enforcing member and opposing bi-planar sheets. As such, the sheets, track members and hollow elongate re-enforcing members are mutually secured and are thereby maintained in close proximity to each other, minimizing the potential effect of any bending moments caused by gravity or direct impacts. That is, my system functions to diffuse or transfer shear forces from the center to the edges of the supporting substructure. In distinction, the structure of Schierding employs two distinct securement cavities, namely, an interior chamber and a region formed at ends of its leg members which are bent outwardly to lie against chords to support a second cavity for a meniscus along ends of the leg members by which a web apex is held. As such, the re-enforcing element is separated from the apex by a considerable distance, referred to in Schierding as a throat portion.
In my system, apart from the differences in use, namely, that of a girder joist of a floor or ceiling versus that of a load-bearing wall in Schierding, the opportunity for such bending moments of shear forces is minimized in that the edges of a planar sheet extend well into the interior of a longitudinal track-like enclosure in combination with the fastener from opposite directions of an open bottom of member to the edges of a bi-planar sheet by the fasteners and an upper area of the enclosure to a re-enforcing member.
Stated otherwise, the system of Schierding does not define a unitary or integrated mechanical system in which each part co-acts in a structurally supportive way with its other parts. Further, given the undulating character of its web, there does not exist an integral securement to the upper or lower edges of the upper interior chamber of the structure. Due to factor welds are necessary to secure the web to each chord. My structure, in distinction, provides a continuous interface of securement of the longitudinal tracks to the bi-planar sheets in addition to the shear force transfer function of the fasteners, discussed above. This structure alone provides a more predictable result than that obtainable by simply substituting a bi-planar surface for the undulating web configuration of Schering. That is, the distance of the re-enforcing element from the apex of the web inherently degrades the stability of the system particularly if it were used with a corrugated geometry of the type of Palmer (U.S. Pat. No. 2,101,090) as a simple substitute for a web of a truss.
In economic terms, the girder structure of Schierding, however combined with Palmer, is not cost-effective for use in load bearing joist girder applications such as substructure of a wall or ceiling as is contemplated herein.